[burgrat]

I have a Diamondback Haanjo Metro bike with mechanical disc brakes (160mm disc front, 140mm disc rear). They are not great and I want to upgrade to hydraulic disc brakes. Looking at getting Shimano BR-MT201 brakes.
Can I simply switch these out, or do I need to buy an adaptor mount? Does the disc size matter (ie do the brakes work with a 160mm and a 140mm disc)? I'm just learning about disc brakes and I can't seem to find the answers or I'm not understanding well. Any help is appreciated!
Thanks!

 

[Reaperactual]

Swap away, all good! 👍

Changing rotors for bigger diameter versions require adaptors to be fitted or replaced. Those Hydro's will fit and a straight forward swap.

The other thing to be aware of is different brakes that use different pad types/shape that may not be compatible with the depth of the rotor's braking band/pad contact surface.

Your current Tektro Aires and the new MT201 Hydro's use the same pads so no issues, you're good to go.

Imo it's a worthwhile upgrade swapping out entry level cable operated for hydraulic brakes. 😎

 

[burgrat]

Thanks for your help!

 

[Taroroot]

From what I can see from the pics, your bike is post mount calipers, so you should be good. most road disc frames use flatmount, that would be the one thing to watch out for, but yours does not look like it. There's IS mount, which is hardly used anymore, but my cross bike uses it for fork, I don't think you have to worry about that one.

 

[burgrat]

Do these photos help? Thank you guys for the feedback. I don't know discs too well, obviously.

 

[Taroroot]

Yup post mount on both ends, you’re good!

 

[Reaperactual]

Yes the pictures help @burgrat!

Had a closer look at the front after reading @Taroroot's comments.

All good on the Post Mount rear.

It seems you do have an I.S. mount on the front with two bolts visible:-

Behind the I.S. mount is a 160mm I.S. adaptor bolted to it:-

All still should be fine but when you mount the new hydro caliper just make sure you have clearance between the underside of the caliper and the I.S. adaptor.

It's important that the caliper contacts properly at the top and bottom of the adaptor (where the caliper bolts thread through) for correct, safe fit and caliper centering afterwards.

 

[burgrat]

Thank you guys so much for the help! You're awesome!